treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 434

Based on 1 normalized pattern(s):

  under gplv2 only

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 1 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190114.847550565@linutronix.deSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/pinctrl/pinctrl-at91.c

+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * at91 pinctrl driver based on at91 pinmux core
  *
  * Copyright (C) 2011-2012 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
- *
- * Under GPLv2 only
  */
 
 #include <linux/clk.h>